Display device and method of manufacturing a display device

ABSTRACT

A manufacturing method of a display device in an embodiment according to the present invention, the method includes forming a terminal electrode in a terminal part of a first substrate, forming a pixel electrode corresponding to each pixel in a pixel part of the first substrate, forming a first intermediate layer in a region including the terminal electrode of the terminal part, forming an organic layer above the pixel electrode in the pixel part, forming a counter electrode layer above the first substrate including the pixel part and the terminal part, forming a passivation layer above the counter electrode layer, arranging a second substrate opposing the pixel part and bonding the first substrate and the second substrate using a sealing member enclosing the pixel part, and removing the first intermediate layer, the counter electrode layer and the passivation layer in the terminal part.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2016-062958, filed on Mar. 28,2016, the entire contents of which are incorporated herein by reference.

FIELD

One embodiment of the present invention is related to a display deviceincluding a terminal part and a pixel part and a method of manufacturingthe display device.

BACKGROUND

A liquid crystal display device utilizing the electro-optical effects ofliquid crystals or an organic electroluminescence display device usingan organic electroluminescence element are being developed as displaydevices to be used in electric appliances or electronic devices. Thesedisplay devices are formed with a display screen using a plurality ofpixels arranged above a substrate. A liquid crystal element or anorganic electroluminescence element is arranged as a display element ineach pixel of the display device. The display device displays video orstill images by driving a pixel part arranged with such pixels using apixel circuit and driving circuit formed by a transistor. The displaydevice includes a terminal part which is applied with a video signal, atiming signal for controlling the operation of a circuit, and power andthe like.

The display device is stacked with an insulation film, semiconductorfilm and conductive film, and by forming these thin films into a certainshape, a wiring pattern for forming a transistor or a circuit iscreated. In this case, each terminal electrode in the terminal part isrequired to be exposed to the exterior of the display device. As aresult, in order to make the terminal part, different processing isrequired for a transistor or display element arranged in a pixel part.Specifically, a process for exposing the surface of each terminalelectrode in the terminal part to an exterior surface is required.

For example, in the manufacturing process of a display device inJapanese Laid Open Patent Publication No. 2004-165068, a method isdisclosed in which an organic insulation layer which functions as alaser removal layer is arranged above a terminal part, and after forminga passivation film covering the entire surface of a substrate, laserlight is irradiated onto the organic insulation layer of the terminalpart covered with the passivation film to generate ablation in theorganic insulation layer and expose a terminal electrode in a terminalregion.

However, since processing control in a depth direction is difficult in amethod for exposing a terminal electrode by irradiating laser light,when attempting to securely expose a terminal electrode, the surface ofthe terminal electrode becomes damaged by the laser light. On the otherhand, processing is complex in a method for exposing a terminalelectrode by etching and there are problems of a drop in yield and anincrease in manufacturing costs. For example, in a terminal part of adisplay device, since a plurality of cover films with differentmaterials are deposited in a manufacturing process, an etching methodfor each layer is required or it is necessary to change an etchingliquid or etching gas, and further manufacturing equipment for exposinga terminal electrode is required.

SUMMARY

A manufacturing method of a display device in an embodiment according tothe present invention, the method includes forming a terminal electrodein a terminal part of a first substrate, forming a pixel electrodecorresponding to each pixel in a pixel part of the first substrate,forming a first intermediate layer in a region including the terminalelectrode of the terminal part, forming an organic layer above the pixelelectrode in the pixel part, forming a counter electrode layer above thefirst substrate including the pixel part and the terminal part, forminga passivation layer above the counter electrode layer, arranging asecond substrate opposing the pixel part and bonding the first substrateand the second substrate using a sealing member enclosing the pixelpart, and removing the first intermediate layer, the counter electrodelayer and the passivation layer in the terminal part.

A display device in an embodiment according to the present inventionincludes a pixel part arranged with a plurality of pixels, and aterminal part arranged with a plurality of terminal electrodes. Theterminal part includes a region in which the terminal electrode isexposed, and a region stacked with an insulation layer, a counteropposing electrode layer and a passivation layer extending from thepixel part to above the terminal electrode, and wherein the counterelectrode layer and the passivation layer have a taper shaped endsurface.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view diagram showing a structure of a displaydevice related to one embodiment of the present invention;

FIG. 2 is a cross-sectional diagram showing a structure of a displaydevice related to one embodiment of the present invention;

FIG. 3 is a cross-sectional diagram showing a structure of a pixel partof a display device related to one embodiment of the present invention;

FIG. 4 is a cross-sectional diagram for explaining a manufacturingprocess of a display device related to one embodiment of the presentinvention;

FIG. 5 is a cross-sectional diagram for explaining a manufacturingprocess of a display device related to one embodiment of the presentinvention;

FIG. 6 is a cross-sectional diagram for explaining a manufacturingprocess of a display device related to one embodiment of the presentinvention;

FIG. 7 is a cross-sectional diagram for explaining a manufacturingprocess of a display device related to one embodiment of the presentinvention;

FIG. 8 is a cross-sectional diagram for explaining a manufacturingprocess of a display device related to one embodiment of the presentinvention;

FIG. 9 is a cross-sectional diagram for explaining a manufacturingprocess of a display device related to one embodiment of the presentinvention;

FIG. 10A is a cross-sectional diagram for explaining a manufacturingprocess of a display device related to one embodiment of the presentinvention and is a diagram for explaining a stage of performing a purewater treatment in a terminal part;

FIG. 10B is a cross-sectional diagram for explaining a manufacturingprocess of a display device related to one embodiment of the presentinvention and is a diagram showing a state of terminal part after a purewater treatment; and

FIG. 11 is a flowchart for explaining a manufacturing process of adisplay device related to one embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

The embodiments of the present invention are explained below whilereferring to the diagrams. However, it is possible to perform thepresent invention using various different forms, and the presentinvention should not be limited to the content described in theembodiments exemplified herein. Although the width, thickness and shapeof each component are shown schematically compared to their actual formin order to better clarify explanation, the drawings are merely anexample and should not limit an interpretation of the present invention.In the specification and each drawing, the same reference symbols areattached to similar elements and elements that have been mentioned inprevious drawings, and therefore a detailed explanation may be omittedwhere appropriate. Notations such as “a” and “b” attached to the end ofa symbol are sometimes used to identify the same element. Furthermore,the characters “first” and “second” attached to each element areconvenient labels used for distinguishing each element and do notcontain any further meaning unless otherwise explained.

In the present specification, in the case where certain parts or regionsare given as “above (or below)” other parts or regions, as long as thereis no particular limitation, these include parts which are not onlydirectly above (or directly below) other parts or regions but also in anupper direction (or lower direction). That is, in the case where certainparts or regions are given as “above (or below)” other parts or regions,other structural elements may be included between other parts or regionsin an upper direction (or lower direction). In the followingdescription, unless otherwise specified, the side on which the secondsubstrate is disposed with respect to the first substrate is referred toas “upper” or “upper direction”, and the opposite side is referred to as“lower” or Will be described as “lower direction”.

A first substrate explained in the present specification includes atleast one planar shaped main surface and each of an insulation layer,semiconductor layer and conductive layer or each of a transistor anddisplay element are arranged above this main surface. In the followingexplanation, in the case where “above”, “upper layer”, “upwards” or“upper surface” are explained with respect to a first substrate using amain surface of the first substrate as a reference in a cross-sectionalview, unless otherwise noted, the main surface of the first substrate isdescribed as a reference.

FIG. 1 shows a perspective view of a display device 100 related to oneembodiment of the present invention. The display device 100 includes afirst substrate 102 and a sealing member 118. A pixel part 104, drivecircuit part 106 (driver IC 105 a, scanning line drive circuit 105 b,switch circuit 105 c) and a terminal part 110 are arranged in a firstsurface of the first substrate 102. The pixel part 104 is arranged witha plurality of pixels 112 in a row direction and column direction. Theterminal part 110 is arranged with a plurality of terminals 114. Thesealing member 118 is arranged so as to cover the pixel part 104 at afirst surface side of the first substrate 102. The sealing member 118 isformed from a glass substrate or organic resin substrate the same as thefirst substrate 102. In addition, instead of a plate shaped member suchas the first substrate, the sealing member 118 is formed by a stackedlayer body with alternately stacked organic resin layers and inorganiclayers. The terminal part 110 is arranged at an end part of the firstsubstrate 102 and on the outer side of the sealing member 118. Inaddition, among the drive circuit parts 106, the drive IC 105 a isarranged on the outer side of a sealing part.

A signal for operating each circuit (drive IC 105 a, scanning line drivecircuit 105 b, switch circuit 105 c) of the drive circuit part 106 isinput via a terminal electrode 114 of the terminal part 110. Theterminal electrode 114 has a conductive electrode surface which isexposed and is connected with a flexible printed circuit substrate 116by an anisotropic conductive layer. The flexible printed circuitsubstrate 116 connects the display device 100 with other functioncircuits or external devices.

A glass substrate or organic resin substrate is used for the firstsubstrate 102. For example, a polyimide substrate is used for theorganic resin substrate. The thickness of the organic resin substratecan be set from a few micrometers to a few tens of micrometers and asheet display having flexibility can be realized. The sealing member 118is formed from a glass substrate or organic resin substrate the same asthe first substrate 102. In addition, instead of a plate shaped membersuch as the first substrate, the sealing member 118 is formed by astacked layer body with alternately stacked organic resin layers andinorganic layers.

Each region of the pixel part 104 and terminal part 110 arranged abovethe first substrate 102 is not separately prepared but prepared duringthe same process. For example, each region is prepared by processing thesame conductive layer as a conductive layer for forming certain wiringincluded in the pixel part 104, or a conductive layer for forming atleast a part of the terminal electrode 114 of the terminal part 110.

FIG. 2 shows a cross-sectional structure of the display device 100. Inaddition, FIG. 3 shows a cross-sectional view for explaining the detailsof a pixel 112 in the pixel part 104. An explanation is given below byappropriately referencing FIG. 2 and FIG. 3.

As is shown in FIG. 2, the display device 100 includes the pixel part104, drive circuit part 106, a sealing part 108 and terminal part 110.The drive circuit part 106 includes a circuit region 107 a and wiringregion 107 b. The pixel part 104 is arranged with a transistor 120,light emitting element 122, first capacitor element 124 and secondcapacitor element 126 above the first substrate 102. Details of theseelements are shown in FIG. 3.

As is shown in FIG. 3, the light emitting element 122 is electricallyconnected with the transistor 120. A current which flows between asource and drain of the transistor 120 is controlled by a video signalapplied to a gate and light emitting luminosity of the light emittingelement 122 is controlled by this current. The first capacitor element124 stores a gate voltage of the transistor 120 and the second capacitorelement 126 is arranged for adjusting the amount of current flowing tothe light emitting element 122.

A base insulation layer 128 is arranged on the first surface of thefirst substrate 102. The transistor 120 is arranged above the baseinsulation layer 128. The transistor 120 has a structure in which asemiconductor layer 130, gate insulation layer 132 and gate electrode134 are stacked. The semiconductor layer 130 is an amorphous orpolycrystalline silicon or an oxide semiconductor and the like. Asource/drain electrode 138 is arranged in an upper layer of the gateelectrode 134 via the first insulation layer 136. A second insulationlayer 140 is arranged as a leveling layer in an upper layer of thesource/drain electrode 138. The first insulation layer 136 is formed byan inorganic insulation material such as silicon oxide or siliconnitride, and the second insulation layer 140 is formed from an organicinsulation material such as polyimide or acrylic.

The light emitting element 122 is arranged in an upper surface of thesecond insulation layer 140. The light emitting element 122 has astructure in which a pixel electrode 144 electrically connected with thetransistor 120, an intermediary layer 146, organic layer 148 and counterelectrode layer 150 are stacked. The light emitting element 122 is atwo-terminal element and emitted light is controlled by controlling avoltage between the pixel electrode 144 and the counter electrode layer150. In addition, a bank layer 154 formed from an organic insulationmaterial is arranged above the second insulation layer 140 in order tocover a periphery edge part and expose an inner side region of the pixelelectrode 144. The counter electrode layer 150 is arranged in an uppersurface of the organic layer 148 and is arranged from above the pixelelectrode 144 to an upper surface part of the bank layer 154.Furthermore, the bank layer 154 covers a periphery edge part of thepixel electrode 144 and is formed from an organic resin material to forma gentle step at an end part of the pixel electrode 144. Acrylic orpolyimide and the like are used for the organic resin material.

The organic layer 148 includes a light emitting material such as anorganic electroluminescence material. The organic layer 148 is formedusing a low molecular or high molecular organic material. In the casewhere a low molecular organic material is used, in addition to a lightemitting layer including an organic material with light emittingproperties, the organic layer may also be formed including a holeinjection layer and electron injection layer sandwiching the lightemitting layer, and may further include a hole transport layer andelectron transport layer. For example, the organic layer 148 can beformed with a structure in which a light emitting layer is sandwiched bya hole injection layer and an electron injection layer. In addition, theorganic layer 148 may be appropriately added with a hole transportlayer, electron transport layer, hole block layer and electron blocklayer in addition to a hole injection layer and electron injection layerand the like. Although not shown in the diagram, a formation end of theorganic layer may be designed to extend as far as the terminal part.

The intermediate layer 146 arranged between the pixel electrode 144 andorganic layer 148 is formed from a material including carbon. Forexample, the intermediate layer 146 is formed from amorphous carbon. Theintermediate layer 146 is arranged in order to increase carrierinjection properties from the pixel electrode 144 to the organic layer48. The thickness of the intermediate layer 146 is formed between 1nm˜10 nm, 3 nm for example.

Furthermore, in one embodiment of the present invention, the lightemitting element 122 includes a top-emission type structure in whichlight emitted by the organic layer 148 is irradiated to the counterelectrode layer 150 side. As a result, the pixel electrode 144 ispreferred to have light reflecting properties. Apart from being formedby a metal material with light reflecting properties such as aluminum(Al) and silver (Ag), the pixel electrode 144 may include a structure inwhich a transparent conductive layer formed from ITO (Indium Tin Oxide)or IZO (Indium Zinc Oxide) which have excellent hole injectionproperties, and a metal layer with light reflecting properties arestacked.

Since light emitted by the organic layer 146 passes through the counterelectrode layer 148, it is preferred to be formed by a transparentconductive film such as ITO or IZO having translucency and conductivity.

The first capacitor element 124 is formed in a region in which thesemiconductor layer 130 and first capacitor electrode 135 overlap withthe gate insulation layer 132 as a dielectric layer. In addition, thesecond capacitor element 126 is formed with the second capacitorelectrode 141 arranged overlapping the pixel electrode 144, and a thirdinsulation layer 142 arranged between the pixel electrode 144 and secondcapacitor electrode 141 as a dielectric layer.

The passivation layer 152 is arranged above the light emitting element122. The passivation layer 152 is arranged to prevent water and the likefrom infiltrating the light emitting element 122. A material havingtranslucency such as an inorganic insulation layer of silicon nitride oraluminum oxide and the like is preferred as the passivation layer 152.In addition, the passivation layer 152 may have a structure in whichthis inorganic insulation layer and an organic insulation layer arestacked.

A color filter layer 160 and light blocking layer 162 may be arranged inthe sealing member 118. When white light is emitted from the lightemitting element 122, it is possible to set light of a specificwavelength band as the light emitted from a pixel 112 by arranging thecolor filter layer 160. In addition, in the case where light emittedfrom the light emitting element 122 is light of a specific wavelengthband (for example, blue color band, green color band, red color band),it is possible to increase color purity of light emitted from a pixel122 by arranging a color filter layer 160 matching the emitted light.

In FIG. 2, a circuit region 107 a of the drive circuit part 106 isformed with a scanning line drive circuit 105 b and switch circuit 105 cby transistors 121 a, 121 b. For example, the transistor 121 a is ann-channel type transistor and the transistor 121 b is a p-channel typetransistor. In addition, the counter electrode layer 150 extends fromthe pixel part 104 to the wiring region 107 b.

An opening part 164 which passes through the second insulation layer 140is arranged in the wiring region 107 b. The opening part 164 is arrangedalong at least one side of the pixel part 104. The second insulationlayer 140 is separated into the pixel part 104 side and an end part sideof the first substrate 102 by the opening part 164. In addition, thebank layer 154 is also similarly separated by the opening part 164. Thethird insulation layer 142 above the second insulation layer 140, andthe counter electrode layer 150 arranged on an upper surface of the banklayer 154 are arranged along the opening part 164. That is, the thirdinsulation layer 142 is arranged along a side surface (side surface ofthe second insulation layer 140) of the opening part 164 and a bottomsurface (upper surface of the first insulation layer 136) of the openingpart 164.

In this way, a sealing structure is formed by separating the secondinsulation layer 140 formed by an organic insulation material and thebank layer 154 using the opening part 164, and by arranging the thirdinsulation layer 142 formed from an inorganic material and the counterelectrode layer 150 so as to cover a side surface and bottom surface ofthe opening part 164. The third insulation layer 142 is arranged inclose contact at a bottom part of the opening part 164. In this way, bysandwiching the second insulation layer 140 and bank layer 154 formedfrom an organic insulation material between layers of an inorganicmaterial, it is possible to prevent water and the like from infiltratingto the pixel part 104 from the sealing part 108 side. That is, thisstructure prevents water from passing through the second insulationlayer 140 and bank layer 154 formed from an organic insulation materialand infiltrating a region in the pixel part 104. A region in which theopening part 164 which divides the second insulation layer 140 and banklayer 154 is arranged can function as a water blocking region 172 andthis structure can be called a “water blocking structure”.

A contact part 170 in which the counter electrode layer 150 iselectrically connected with a lower layer wiring 168 may also beincluded in the drive circuit part 106. The counter electrode layer 150is controlled to a certain voltage by being connected to the wiring 168.Furthermore, a contact hole 167 is arranged in the second insulationlayer 140 in the case where a connection is formed by the wiring 168 barranged above the second insulation layer 140 and the wiring 168 aarranged above the first insulation layer 136.

A sealing material 158 is arranged in the sealing part 108. The sealingmaterial 158 adheres the first substrate 102 and sealing member 118together. A region sandwiched by the first substrate 101 and sealingmember 118 is blocked off from the air by the sealing material 158. Thepixel part 104 is arranged in an enclosed space sandwiched by the firstsubstrate 102, sealing member 118 and sealing material 158. Furthermore,a filler 156 may be arranged in a space part between the first substrate102 and sealing member 118.

The terminal part 110 is arranged with a terminal electrode 114. Theterminal electrode 114 includes a first terminal layer 115 a and secondterminal layer 115 b. The first terminal layer 115 a is arranged usingthe same layer as the conductive layer which forms the source/drainelectrode 138 for example. The first terminal layer 115 a may also havethe same layer structure in the case where the source/drain electrode138 has a stacked structure arranged with a titanium (Ti) layer on anupper layer side and lower layer side of aluminum (Al). In addition, thefirst terminal layer 115 a may also be formed by the same conductivelayer as the gate electrode 134. The second terminal layer 115 b isformed using a conductive metal oxide film. For example, the secondterminal layer 115 b is formed using a transparent conductive film suchas ITO or IZO. Since this type of second terminal layer 115 b is hardcompared to the first terminal layer 115 a and has conductivity evenwhen oxidized, it can be suitably arranged as a top surface layer of theterminal electrode 114.

Although the base insulation layer 128, gate insulation layer 132, firstinsulation layer 136, second insulation layer 140, third insulationlayer 142, counter electrode layer 150 and passivation layer 152 arearranged on roughly the entire surface above the first substrate 102, aregion is included in which the second insulation layer 140, thirdinsulation layer 142, counter electrode layer 150 and passivation layer152 arranged on an at least an upper layer side of the terminalelectrode 114 is removed in the terminal part 110. The terminalelectrode 114 is exposed to an outer surface by this removed region.

Conventionally, each of the second insulation layer 140, thirdinsulation layer 142, counter electrode layer 150 and passivation layer152 are processed by wet-etching or dry-etching to expose the uppersurface of the terminal electrode 114. However, in one embodiment of thepresent invention, the terminal electrode 114 is exposed by an easiermethod without such an etching process. Details of this process areexplained below according to the manufacturing process of the displaydevice 100.

FIG. 4 shows a stage at which the base insulation layer 128, transistor120 of the pixel part 104 (formed including the semiconductor layer 130,gate insulation layer 132 and gate electrode 134), and first capacitorelement 124 (formed using the first capacitor electrode 135, gateinsulation layer 132, and source/drain electrode 138), transistors 121a, 121 b of the drive circuit part 106, first terminal 115 a of theterminal part 110, first insulation layer 136, source/drain electrode138, and second insulation layer 140 are formed on a first surface ofthe first substrate 102. The transistor 120 of the pixel part 104 andthe transistors 121 a, 121 b of the drive circuit part 106 have the samestructure. In addition, the first terminal layer 115 a of the terminalpart 110 is formed using the same conductive layer as the source/drainelectrode 138 above the first insulation layer 136. For example, thefirst terminal layer 115 a has a structure in which three layers of atitanium (Ti) layer, aluminum (Al) layer and titanium (Ti) layer arestacked from a lower layer side.

As is shown in FIG. 4, the first insulation layer 136 is formed by asingle layer or a plurality of layers. For example, the first insulationlayer 136 is formed by stacking a silicon nitride film and silicon oxidefilm. This type of first insulation layer 136 is manufactured by aplasma CVD method or sputtering method. The second insulation layer 140formed above the first insulation layer 136 is formed from an organicinsulation material. It is preferred that a high molecular material suchas polyester, polyamide, polyimide and polysiloxane be included as theorganic insulation material. The second insulation layer 140 is formedon roughly the entire surface of the first substrate 102 using aspincoat method, an inkjet method, a laminate method, a printing method,a dip coating method or vapor deposition polymerization method using theorganic insulation material. The second insulation layer 140 ispreferred to be formed at a thickness of 1 micrometer or more. In thisway, it is possible to bury irregularities due to the transistor 120 bythe second insulation layer 140 to form a flat surface above the firstsubstrate 102.

FIG. 5 shows a stage at which the second capacitor electrode 141 isformed above the second insulation layer 140 in the pixel part 104, anda contact hole 166 passing through the second insulation layer 140reaching the source/drain electrode 138 and the opening part 164 arearranged. Furthermore, a contact hole 167 is formed in the secondinsulation layer 140 in the case where wiring 168 a is arranged abovethe first insulation layer 136. A part of the second insulation layer140 covering the upper surface of the first terminal layer 115 a in theterminal part 110 is also removed at the same time as the contact hole166 is formed. Furthermore, a photolithography process is performedafter film formation of the second insulation layer 140 in the casewhere the second insulation layer 140 is formed from a photosensitiveorganic insulation material, and formation of the contact hole 166 andformation of a removal pattern of the terminal part 110 are performed bydevelopment and sintering.

The third insulation layer 142 is manufactured by a silicon nitride filmor silicon oxide film. The third insulation layer 142 is manufactured onroughly the entire surface of the first substrate 102 by a plasma CVDmethod or sputtering method without using a shadow mask when forming afilm. When the third insulation layer 142 is formed after formation of acontact hole, the bottom surface of the contact hole 166 becomes coveredby the third insulation layer 142. In this case, it is preferred that anopening part 169 is arranged overlapping the contact hole 166 also inthe third insulation layer 142. It is possible to remove the thirdinsulation layer 142 formed on the upper surface of the first terminallayer 115 a at the same time as forming the opening part 169.

Furthermore, it is preferred that the second terminal layer 115 b isformed above the first terminal layer 115 a at this stage. The secondterminal layer 115 b may be formed in the same conductive layer as thesecond capacitor electrode 141 or formed in the same conductive layer asother wiring or electrodes formed in the pixel part 104 or drive circuitpart 106. The second terminal layer 115 b is preferred to be formed by atransparent conductive film such as ITO or IZO.

A circuit including a transistor is formed in the pixel part 104 anddrive circuit part 106 and the terminal electrode 114 is formed in theterminal part 110 above the first substrate 102 by the stages up tothose described above. In the following process, the pixel electrode 144is formed (S201), an intermediate layer is formed (S202), an organiclayer is formed (S203), a counter electrode layer is formed (S204), apassivation layer is formed (S205), a sealing member is attached (S206),and a process for exposing a terminal electrode is performed (S208) asis shown in FIG. 11. When a plurality of display panels is taken from amother glass substrate (large area substrate), a separation process of amother glass substrate (S207) is performed between steps S206 and S207.

FIG. 6 shows a stage (S201) where the pixel electrode 144 is formed. Thepixel electrode 144 is formed using ITO or IZO as a transparentconductive film in the case where light emitted from the light emittingelement 122 is emitted to the first substrate 102 side. In addition, inthe case where light emitted from the light emitting element 122 isemitted to the counter electrode layer 150 side as in the presentembodiment, a metal such as aluminum (Al) or silver (Ag) or an alloy ofthese is used. Alternatively, the pixel electrode 144 is formed bystacked layers of these metal layers and a conductive metal oxide layer.For example, the pixel electrode 144 is manufactured from a stackedlayer structure (for example, ITO/Ag/ITO) in which a metal layer issandwiched by conductive metal oxide layers. In addition, the secondcapacitor element 126 is formed by the pixel electrode 144, the secondcapacitor electrode 141 and the third insulation layer 142 sandwichedtherebetween.

At this stage, wiring 168 b connected with wiring 168 a is formed in thecontact hole 167 formed in the second insulation layer 140 in order toform the contact hole 170 of the counter electrode layer 150 in thedrive circuit part 106. The wiring 168 b can be formed using the sameconductive layer as the pixel electrode 144.

After forming the pixel electrode 144, the bank layer 154 is formedusing an organic insulation material. The bank layer 154 buries a stepcaused by the contact holes 166, 167 formed in an end part of the pixelelectrode 144 and the second insulation layer 140. Furthermore, thistype of bank layer 154 is sometimes called a separation wall or rib. Thebank layer 154 can be formed using a material usable for the secondinsulation layer 140 such as acrylic resin or polyimide resin. The banklayer 154 is formed with an opening part so as to expose the pixelelectrode 144, a bottom part of the opening part 164 and an uppersurface of the wiring 168 b. An end part of the opening part of the banklayer 154 is preferred to have a smooth taper shape. When the end partof the opening part of the bank layer 154 has a steep gradient, thecovering properties of the subsequently formed organic layer 148 and thelike become poor which easily leads to defects. In addition, the banklayer 154 is formed so as to not be arranged on an upper surface of theterminal electrode 114 in the terminal part 110. That is, as describedpreviously, the bank layer 154 is formed so that the upper surface partof the terminal electrode 114 is also open when forming an opening partof the bank layer 154.

FIG. 7 shows a stage (S202) where an intermediate layer is formed. Theintermediate layer 146 is formed using an amorphous carbon film forexample. This type of intermediate layer 146 is manufactured so that acover film is formed in a certain region using a shadow mask (thin platehaving an opening part) on a film formation surface (first surface) ofthe first substrate 102. Specifically, an intermediate layer 146 a isformed above the pixel electrode 144 of the pixel part 104 and above thebank layer 154. In addition, at the same time, an intermediate layer 146b is also formed above the terminal electrode 144. The intermediatelayer 146 b is formed above the second terminal layer 115 b. Theintermediate layer 146 is formed by a sputtering method. At this time,it is possible to simultaneously manufacture the intermediate layer 146a of the pixel part 104 and the intermediate layer 146 b of the terminalpart 110 by arranging a shadow mask on a first surface side of the firstsubstrate 102 and performing film formation. The thickness of theintermediate layer 146 is 1 nm to 10 nm as described above and is formedto a film thickness of 3 nm for example.

FIG. 8 shows a stage where the organic layer 148, counter electrodelayer 150 and passivation layer 152 are formed. Formation of the organiclayer 148 is performed after formation of the intermediate layer 146(S203). The organic layer 148 is formed so as to overlap theintermediate layer 146 a at least above the pixel electrode 144. Forexample, the organic layer 148 is formed using the same shadow mask aswhen forming the intermediate layer 146 by a vacuum deposition method.The organic layer 148 includes an organic electroluminescence materialand is formed by a single layer or plurality of layers. For example, theorganic layer 148 is formed by appropriately combining a carrierinjection layer, a carrier transport layer, a light emitting layer, acarrier blocking layer and an exciton blocking layer. Furthermore, theorganic layer 148 has a different material to that included in anadjacent pixel and light emitting layer, and may be formed so that otherlayers such as a carrier transport layer have the same structure. Inthis way, it is possible to obtain emitted light of different colorsbetween pairs of adjacent pixels and full color display is possible. Inthis case, the color filter layer 162 and light blocking layer 164 shownin FIG. 8 become unnecessary (not shown in the diagram). Reversely, thesame organic layer 148 may be used in all the pixels. In this case, theorganic layer 148 which emits white light for example may be formed inadvance so as to be shared by all the pixels, and the wavelength oflight to be extracted from each pixel using a color filter and the likemay be selected.

The counter electrode layer 150 is formed after the organic layer 148 isformed (S204). The counter electrode layer 150 is formed by a conductivelayer having translucency using a sputtering method. In the presentembodiment, since the light emitting element 122 is a top-emission typewhich emits light from the counter electrode layer 150 side, it ispreferred that the film thickness of the counter electrode layer 150 isuniform. In the present embodiment, a method which does not use a shadowmask when forming a conductive film by a sputtering method is adopted inorder to increase film thickness uniformity of the counter electrodelayer 150.

In a sputtering device, a shadow mask made from metal is adhered by amagnet buried in a substrate holder. In this case, when plasma densityin the vicinity of the substrate changes due to magnetic field leakagefrom the magnetic for adhering, the film thickness of a cover film to bedeposited on the substrate varies and becomes dependent on thearrangement position of the magnet for adhering. That is, uniformity ofa cover film formed by sputtering drops.

In order to solve such a problem, uniformity of the film thickness ofthe counter electrode layer 150 is increased in the present embodimentby film formation without using a shadow mask as described above.Furthermore, a metal film such as aluminum (Al) or gold (Au) which has afilm thickness to the extent that visible light passes through, or aconductive metal oxide cover film such as ITO or IZO is used as thecounter electrode layer 150. In this case, a thin film such as Li—Al,Mg—Ag, Mg—Al may be arranged between organic layers 148 in order toincrease carrier injection properties.

An electrical connection with the wiring 168 b is formed in the contactpart 170 by arranging the counter electrode layer 150 from the pixelpart 104 to the contact part 170 arranged in the drive circuit part 106.

The passivation layer 152 is formed after formation of the counterelectrode layer 150 (S205). The passivation layer 152 has a function toprevent the infiltration of water to the light emitting element 122 fromthe exterior. It is preferred that the passivation layer 152 is formedusing a film with high barrier properties to water vapor. For example,it is preferred that the passivation layer 152 is formed using aninorganic insulation material such as silicon nitride, silicon oxide,silicon nitride oxide or silicon oxide nitride. In addition, thepassivation layer 152 may also be formed by combining a layer of theinorganic insulation materials described above with an organicinsulation material including acrylic resin, polysiloxane, polyimide andpolyester and the like. For example, the passivation layer 152 may havea three layer structure in which a layer of the inorganic insulationmaterials described above is arranged on a lower layer side and upperlayer side of an organic insulation layer using the organic insulationmaterials described above. In this way, by arranging a plurality ofinorganic insulation layers having water vapor barrier propertiesinterposed by an organic insulation layer, it is possible for otherinorganic insulation layers to compensate for defects such as pinholesformed in a part of an inorganic insulation layer and thereby increasewater vapor barrier properties.

The passivation layer 152 is formed using a sputtering method or plasmaCVD method in the case of an inorganic insulation layer. In addition, itis possible to use a coating method and a vapor depositionpolymerization method and the like in the case of an organic insulationlayer. This type of passivation layer 152 is formed on roughly theentire surface of the first substrate 102 without using a shadow maskand the like.

Here, it is possible to further increase barrier properties to watervapor by further forming the passivation layer 152 in a region in whichthe first insulation layer 136 and third insulation layer 142 contact ata bottom surface in the opening part 164 of the second insulation layer140. In addition, by arranging the passivation layer 152 to cover thecontact part 170, it is possible to increase reliability of anelectrical connection state between the counter electrode layer 150 andwiring 168 b.

Following this, the sealing member 118 is arranged in the firstsubstrate 102 from above the passivation layer 152 as is shown in FIG. 9(S206). In the case where the sealing member 118 is a glass or plasticplate shaped component having translucency, the sealing member 118 isattached to the first substrate using the sealing material 158. A colorfilter layer 160 or light blocking layer 162 may also be arrangedmatching the arrangement of a pixel in the sealing member 118. The lightblocking layer 162 is preferred to be formed using a metal withcomparatively low reflectance such as chrome or molybdenum, or amaterial in which black or an equivalent colorant is contained in aresin material. In this way, a function is provided for blockingscattered light or external reflected light other than the light emittedfrom the light emitting element 122. The color filter layer 160 isdifferent for each adjacent pixel and can be formed so as to extractred, green and blue emitted light for example. A counter substrate maybe arranged between the light blocking layer 162 and color filter layer160 via a base film, and an overcoat layer may be further arranged so asto cover the light blocking layer 162 and color filter layer 160.

Furthermore, the sealing member 118 is arranged to cover the pixel part104 and at least one part of the drive circuit part 106 above the firstsubstrate 102, and on the other hand may also be arranged so as to notoverlap the terminal part 110. In addition, the first substrate 102 andsealing member 118 may be arranged with a gap therebetween. A filler 156may be arranged in the gap part between the first substrate 102 andsealing member 118. In addition, an inactive gas may also be filled intothe gap part. It is preferred that high transparency to visible light isprovided in the case where a filler is used. A gap may be adjusted sothat a spacer is interposed when the sealing member 118 is fixed to thefirst substrate 102.

When the display panel is multifaced by the mother glass substrate(large area glass substrate), a separation process into individualdisplay panels is performed at this stage (S207). In this way, astructure is formed in the first substrate 102 in which at least an endpart of the terminal part 110 is exposed. In addition, even in the casewhere a display panel is manufactured not on a mother glass substratebut on individual substrates, a process for separating an end part ofthe terminal part 110 and exposing an end surface is performed.

Finally, a process for exposing the terminal electrode 114 in theterminal part 110 is performed (S208). In the processes hereto, at leastthe counter electrode layer 150 and passivation layer 152 are formedabove the terminal electrode 114. Therefore, a process for removingthese layers and exposing the terminal electrode 114 is necessary thesame as a conventional process.

This process is performed by a pure water treatment in the presentembodiment. That is, the terminal electrode 114 is exposed by a wetprocess using pure water without performing wet etching using a chemicalliquid having acidity or alkalinity, or a dry etching process performedby introducing an etching gas to a vacuum device.

FIG. 10A shows a partial expanded view of the terminal part 110. In theterminal part 110, the terminal electrode 114 (structure including thefirst terminal layer 115 a and second terminal layer 115 b) is formedabove the base insulation layer 128, gate insulation layer 132 and firstinsulation layer 136 for example, and the counter electrode layer 150and passivation layer 152 are formed covering the terminal electrode114. In addition, the intermediate layer 146 is arranged between thesecond terminal layer 115 b of the terminal electrode 114 and thecounter electrode layer 150.

Here, a wet treatment using pure water is performed. In this way, purewater infiltrates to the intermediate layer 146 b which is exposed atthe end surface of the terminal part 110 and peeling occurs. Peeling ofthe intermediate layer 146 b occurs from the boundary with the secondterminal layer 115 b. In this way, the counter electrode layer 150 andpassivation layer 152 which exist on a layer above the intermediatelayer 146 b are removed at the same time in a region in which theintermediate layer 146 b is present. In this way, the terminal electrode114 becomes exposed. Furthermore, in the case where the formation end ofthe organic layer 148 is designed to extend as far as the terminal part110, this part of the organic layer is similarly removed.

Although this process is the same as a lithography process, since theintermediate layer 146 has immersion properties (quality allowing waterto soak through) in the present embodiment, a decrease in the adhesionstrength of at least the intermediate layer 146 is utilized.Specifically, the intermediate layer 146 is formed using amorphouscarbon in the present embodiment. In this case, it is preferred that anamorphous carbon layer is formed into a low density film so that watercan infiltrate.

FIG. 10B shows the form of a terminal part after a pure water treatment.In the terminal part 110, it is preferred that the intermediate layer146 b not only on an upper surface of the terminal electrode 114 (uppersurface of the second terminal layer 115 b) but also overlapping thethird insulation layer 142 extending to a part of the terminal part 110.That is, the third insulation layer 142 is arranged so that an end partis positioned in a region to the inner side from an outer end part ofthe terminal electrode 114 (in other words, outer end part of the secondterminal layer 115 b), and the intermediate layer 142 is arranged tooverlap with the second terminal layer 115 b and a part of the thirdinsulation layer 142. In this way, it is possible to arrange an end partof the counter electrode layer 150 and the passivation layer 152 abovethe third insulation layer 142 as is shown in FIG. 10B. As a result, itis possible to securely prevent short circuits between the counterelectrode layer 150 and terminal electrode 114. In addition, by liftingoff the counter electrode layer 150 and passivation layer 152 by usingthe intermediate layer 146 b as a layer with immersion properties, it ispossible to form the end part of the counter electrode layer 150 andpassivation layer 152 into a taper shape. In this way, it is possible toincrease adhesion with an anisotropic conductive layer arranged abovethe terminal electrode 114.

Furthermore, since the intermediate layer 146 a arranged in the pixelpart 104 is sealed by the passivation layer 152 and also sealed by thesealing member 118, it is not affected in any way by a pure watertreatment. Therefore, it is possible to process the terminal part 110without affecting in anyway the light emitting properties of the lightemitting element 122. In the present embodiment, it is possible to formone or both of the intermediate layer 146 a in the pixel part 104 andintermediate layer 146 b in the terminal part 110 using a layer withimmersion properties (amorphous carbon for example), and it is possibleto reduce the adhesive strength of the intermediate layer 146 b in theterminal part 110 by wet processing.

Furthermore, in the process for exposing the terminal electrode 114, apart of the residue of the intermediate layer 146 b may be left abovethe terminal electrode 114 or above the third insulation layer 142, orat an end surface of the counter electrode layer 150. Since thethickness of the intermediate layer 146 is 1 nm to 10 nm, for example 3nm, even if a fine amount of carbon remains, conductivity with ananisotropic conductive film is never affected. That is, since it is notnecessary to completely remove the intermediate layer 146 b, it ispossible to provide the conditions for exposing the terminal electrode114 with a degree of freedom and increase processing simplicity(margin).

As described above, it is possible to manufacture the display device 100with the structure explained in FIG. 2.

According to one embodiment of the present invention, it is possible toarrange the same layer (intermediate layer 146 b in the presentembodiment) as a part of a layer (intermediate layer 146 a in thepresent embodiment) which forms the pixel part 104 or drive circuit part106, in the terminal part 110, and using this layer to remove a layerformed above the terminal electrode 114 by lithography, it is possibleto simplify the process for exposing the terminal electrode 114. Inaddition, in this case, since it is not necessary to arrange a speciallayer only in the terminal part 110, processing is simplified andmanufacturing costs do not increase.

Furthermore, although an example is exemplified in the presentembodiment in which amorphous carbon is used as the intermediate layer146 arranged in the terminal part 110, the present invention is notlimited to this example. For example, it is possible to replaceamorphous carbon with another material if it is a cover film withimmersion properties to water. For example, it is possible to use a lowdensity zinc oxide film manufactured by a sputtering method, or a lowdensity amorphous silicon film manufactured by a plasma CVD method.

In addition, although the present embodiment exemplified a displaydevice arranged with a light emitting element in a pixel, the presentinvention is not limited to this structure, and the present embodimentcan also be applied to a liquid crystal display device for example.

What is claimed is:
 1. A manufacturing method of a display device, themethod comprising: forming a terminal electrode in a terminal part of afirst substrate; forming a pixel electrode corresponding to each pixelin a pixel part of the first substrate; forming a first intermediatelayer in a region including the terminal electrode of the terminal part;forming an organic layer above the pixel electrode in the pixel part;forming a counter electrode layer above the first substrate includingthe pixel part and the terminal part; forming a passivation layer abovethe counter electrode layer; arranging a second substrate opposing thepixel part and bonding the first substrate and the second substrateusing a sealing member enclosing the pixel part; and removing the firstintermediate layer, the counter electrode layer and the passivationlayer in the terminal part, wherein the first intermediate layer isformed using amorphous carbon.
 2. The manufacturing method of a displaydevice according to claim 1, the method further comprising: forming asecond intermediate layer between the pixel electrode and the organiclayer, wherein the second intermediate layer is arranged separate fromthe first intermediate layer.
 3. The manufacturing method of a displaydevice according to claim 1, wherein the first intermediate layer, thecounter electrode layer and the passivation layer in the terminal partare removed after an end surface of the terminal part is exposed.
 4. Themanufacturing method of a display device according to claim 2, whereinthe second intermediate layer is formed using amorphous carbon.
 5. Themanufacturing method of a display device according to claim 1, whereinthe first intermediate layer, the counter electrode layer and thepassivation layer are removed by a pure water process.
 6. Themanufacturing method of a display device according to claim 1, whereinthe terminal part is formed by stacking a metal layer and a conductivemetal oxide layer, and the first intermediate layer is formed above theconductive metal oxide layer.
 7. The manufacturing method of a displaydevice according to claim 5, wherein the counter electrode layer and thepassivation layer are peeled away from a boundary between the conductivemetal oxide layer and the first intermediate layer.
 8. The manufacturingmethod of a display device according to claim 5, wherein an insulationlayer is formed having an end part located in a region on an inner sidefrom an external end part of the conductive metal oxide layer in theterminal part, and the first intermediate layer is formed on an uppersurface of the conductive metal oxide layer and the insulation layer. 9.The manufacturing method of a display device according to claim 8,wherein an end part of the counter electrode layer and an end part ofthe passivation layer are formed located over the insulation layer.